1. Field of the Invention
The present invention relates to a focus adjustment unit and camera system, and in detail relates to a focus adjustment unit and camera system for carrying out focusing by moving a focusing lens to a position at which contrast of an image becomes a peak, based on imaged data acquired from an image sensor.
2. Description of the Related Art
In the case of a subject in motion, even if there is focus, the subject moves within a time lag of the shutter after the shutter release button has been operated, and there may be cases of out of focus photographs. A focus adjustment unit is known that has so-called dynamic prediction AF, for predicting focus position at the time of exposure, based on ranging results carried out a plurality of times until the shutter release button is operated. When carrying out dynamic prediction AF, generally, in the case of focus adjustment using a phase contrast method, focus position is predicted based on a history of a plurality of defocus amounts that have been detected, and in the case of focus adjustment using a contrast method focus position is predicted based on a history of a plurality of focus positions that have been detected (refer, for example, to Japanese patent laid-open No. 2010-107711 (laid-open May 13, 2010)). There is also known as focus adjustment unit that carries out so-called C-AF (continuous AF) for carrying out focusing continuously while the shutter release button is being pressed down halfway.